Sebaceous Glands and Scarring Alopecia

Reduction in Sebaceous Glands in Scarring Alopecia

Scarring alopecias are a group of hair loss conditions that are associated with the development of scar tissue or “fibrosis.” The diagnosis of scarring alopecia is far more involved than simply identifying “fibrosis” under the microscope. Even male balding (androgenetic alopecia) can be associated with the development of fibrosis beneath the skin when a biopsy is examined under the microscope.

Scarring alopecias are associated with loss and/or reduction in sebaceous glands (which are shown here in the photo) The sebaceous glands are sometimes referred to in lay terms as the “oil glands.” In addition to loss of oil glands, scarring alopecias are associated with specific patterns of inflammation - particularly inflammation directly targeting the hair follicle itself.

New Research Changing How we Think About Scarring Alopecia

Research in the past 12 months has taught us a few more things about the pathology findings of some scarring alopecias. 

In frontal fibrosing alopecia (FFA), new research has suggested that there are changes that are happening long before “fibrosis” actually takes place. Specifically, one of the earliest steps may be inflammation around the tiny vellus hairs. This seems to occur as the sebaceous glands start disappearing.

In the scarring alopecia known as central centrifugal cicatricial alopecia (CCCA) new research has thrown yet another twist on how we all think about scarring alopecia. New research has suggested that some biopsies of CCCA may not be associated with loss of the sebaceous glands - at least in early stages. This important information has taught us that CCCA may be very different than classic scarring alopecias like lichen planopilaris and frontal fibrosing alopecia where the oil glands start disappearing fairly early in the course of the disease.

Reference

Dina Y et al. JAAD 2018
Miteva M and Sabiq S. Am J Dermatopath 2019